Heat dissipation device

ABSTRACT

A heat dissipation device includes a substrate, a fin assembly located on the substrate, a plurality of heat pipes connecting the substrate and the fin assembly, and a fan fixed on the substrate by a securing device. The securing device includes a holder fixed to the substrate and a plurality of elastic fasteners. The fasteners secure the fan onto the holder and each includes a sandwiched portion sandwiched between the fan and the holder to segregate the fan from the holder.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to heat dissipation for electronic components and, more particularly, to a heat dissipation device utilizing a fastener to fix a fan thereof.

2. Description of Related Art

Computer electronic components, such as central processing units (CPUs), generate large amounts of heat during normal operation. If the heat is not properly dissipated, it can adversely affect operational stability of the electronic components and damage associated electronic devices.

Usually, a heat dissipation device is attached to a top surface of a CPU to dissipate heat therefrom. A typical heat dissipation device includes a heat sink attached to the CPU. The heat sink includes a plurality of fins. A fan is mounted on a top of the fins of the heat sink. It is known that the fan generates vibration when operating. The fins, on which the fan is mounted by a clip, will vibrate with the fan since the fan is directly attached thereto, whereby considerable noise is generated during operation.

What is needed, therefore, is an improved heat dissipation device which can overcome the described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an exploded, isometric view of a heat dissipation device in accordance with the disclosure.

FIG. 2 is a partially assembled, isometric view of the heat dissipation device in FIG. 1.

FIG. 3 is an enlarged isometric view of a fastener for securing a fan of the heat dissipation device in FIG. 1.

FIG. 4 is an inverted, assembled, isometric view of the heat dissipation device in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a heat dissipation device in accordance with an embodiment of the disclosure dissipates heat generated by an electronic component (not shown), such as a CPU. The heat dissipation device comprises a substrate 10 attached to the electronic component, a fan 20 fixed on the substrate 10 by a securing device 30, a plurality of first heat pipes 40 and a second heat pipe 50, and a fin assembly 60 located on the substrate 10.

Also referring to FIG. 2, the substrate 10 comprises a substantially square main body 12, and a supporting bar 14 angles upwardly from a lateral side of the main body 12. A slot 142 is defined between the main body 12 and the supporting bar 14. A step 146 is formed on a top of the supporting bar 14. The main body 12 defines a rectangular hatch (not labeled) receiving a base 122 therein. The base 122 is near an opposite lateral side of the main body 12 and far from the supporting bar 14. A bottom surface of the base 122 is attached to the electronic component. Three grooves 124 are defined in a top surface of the base 122 receiving the first heat pipes 40 therein. The grooves 124 are parallel to each other and parallel to the slot 142.

The fan 20 comprises a fan frame 22. The fan frame 22 is substantially rectangular in shape. Four positioning holes 24 are defined in four corners of the fan frame 24, respectively.

The securing device 30 comprises a substantially U-shaped holder 32 and a plurality of fasteners 34 fixing the holder 32 onto the fan 20.

The holder 32 comprises a rectangular top plate 320 and two side plates 322 extending downwardly from two ends of the top plate 320. The top and side plates 320, 322 are wider than the fan frame 22 of the fan 20. A cutout 3220 is defined in a bottom end of a lateral side, away from the substrate 10, of each side plate 322. Two first ears 3222 extend perpendicularly from top and bottom ends of another lateral side, opposite to the previous lateral side and near the substrate 10, of each side plate 322, respectively. The first ears 3222 are substantially rectangular and have four straight edges. The first ears 3222 of one side plate 322 extend towards the first ears 3222 of another side plate 322, and the first ears 3222 are coplanar. A round hole 3223 is defined in each first ear 3222 through which the fastener 34 extends. A horizontal first fixing tab 3224 extends from a bottom edge of the first ear 3222 at the bottom end of each side plate 322. The first fixing tab 3224 is perpendicular to the first ear 3222 and extends towards the substrate 10. A second ear 3226 extends from the bottom end of the lateral side of each side plate 322. Each of the second ears 3226 is located above a corresponding cutout 3220. The second ears 3226 are substantially rectangular and extend towards each other, parallel to the first ears 3222. A horizontal second fixing tab 3228 extends outwardly from a top edge of each of the second ears 3226. The second fixing tabs 3228 are parallel and extend opposite to the first fixing tabs 3224 A threaded hole 3229 is defined in each of the first and second fixing tabs 3224, 3228 receiving fasteners (not shown) therein.

Corresponding to the number of the first ears 3222, the number of fasteners 34 is four. Referring to FIG. 3, each fastener 34 is integrally made of elastic material, such as rubber, and comprises a head portion 340, a first connecting portion 341, a sandwiched portion 342, a second connecting portion 343, an abutting portion 344 and an inserting portion 345 in series.

The head portion 340 is a discal plate. The sandwiched portion 342 has a configuration similar with the head portion 340, but is cut to define two parallel lateral sides 3420. It is to be understood that, in alternative embodiments, a configuration of the sandwiched portion 342 can be a discal plate or the likes. The first and second connecting portions 341, 343 and the inserting portion 345 are columned. A diameter of the first and second connecting portions 341, 343 is less than that of the head portion 340. First connecting portion 341 is shorter than second connecting portion 343 and smaller than a thickness of the first ears 3222. Second connecting portion 343 is shorter than a depth of the positioning holes 24 of the fan 20. The abutting portion 344 is tapered, with a diameter decreasing from the second connecting portion 343 to the inserting portion 345. The maximum diameter of the abutting portion 344 matches that of the head portion 340, and its smallest diameter matches that of the inserting portion 345 and is less than that of the second connecting portion 343. The abutting portion 344 facilitates reception of the fasteners 34 in the holes 3223 of the first ears 3222 and the positioning holes 24 of the fan 20.

Referring to FIGS. 1 and 2, the number of first heat pipes 40 is three, all U-shaped. Each of the first heat pipes 40 comprises a horizontal heat absorption portion 42 and two heat dissipation portions 44 extending upwardly from two opposite ends of the heat absorption portion 42. The heat absorption portions 42 of the heat pipes 40 are close to each other and received in the grooves 124 of the base 122, absorbing heat from the electronic component. The heat dissipation portions 44 are parallel and received in the fin assembly 60.

The second heat pipe 50 is U-shaped, and comprises a horizontal heat absorption portion 52 and two heat dissipation portions 54 extending upwardly from two opposite ends thereof. The heat absorption portion 52 of the second heat pipe 50 is parallel to and apart from the heat absorption portions 42 of the first heat pipes 40. The heat absorption portion 52 is received in the slot 142 of the substrate 10, absorbing heat from the electronic component. The heat dissipation portions 54 are parallel to each other and to the heat dissipation portions 44 of the first heat pipes 40. The heat dissipation portions 54 are received in the fin assembly 60.

The fin assembly 60 comprises a first fin unit 62, a second fin unit 64, a third fin unit 66 and a fourth fin unit 68. The fourth fin unit 68 is arranged on the substrate 10. The third fin unit 66 is arranged on the fourth fin unit 68. The second fin unit 64 is arranged on the third fin unit 66. The first fin unit 62 covers the second fin unit 64.

The first, second and third fin units 62, 64, 66 are substantially rectangular, with a plurality of channels (not labeled) defined therebetween. The first fin unit 62 comprises a first main body 620 and two first flanges 6622 extending downwardly from two lateral sides thereof. The second fin unit 64 comprises a plurality of parallel fins each having a rectangular second main body 640 and two second flanges 642 extending downwardly from two lateral sides thereof. The third fin unit 66 comprises a third main body 660 and two third flanges 662 extending downwardly from two lateral sides thereof. The fourth fin unit 68 comprises a fourth main body 680 and two lateral walls 682 extending downwardly from two lateral sides thereof. The first, second, third and fourth main bodies 620, 640, 660, 680 are of an identical size and longer than the substrate 10. The first flanges 622 of the same height as the second and third flanges 642, 662, and the walls 682 are taller than the first, second and third flanges 622, 642, 662. A bottom of one of the walls 682 is located on the step 146 of the supporting bar 14.

A receiving hole 69 is defined in an end, which extrudes out of the substrate 10, of each of the third and fourth main bodies 660, 680. The receiving holes 69 cooperate to define a receiving space 690 receiving the fan 20 and the securing device 30 therein. A plurality of openings 61 are defined in the first, second, third and fourth main bodies 620, 640, 660, 680, for cooling air impelled by the fan 20 flowing therethrough. A plurality of first holes 63 are defined in the second, third and fourth main bodies 640, 660, 680, receiving the heat dissipation portions 44 of the first heat pipes 40. Two second holes 641 are defined in a lateral side of the second main bodies 640 corresponding to the supporting bar 14 of the substrate 10, receiving the heat dissipation portions 54 of the second heat pipe 50. A hole 602 is defined in each of the third and fourth main bodies 660, 680 corresponding to one of the second holes 641 of the second main bodies 640, receiving one of the heat dissipation portions 54 of the second heat pipe 50 therein. Another heat dissipation portion 54 of the second heat pipe 50 is received in the receiving space 690 and is attached to the third and fourth main bodies 660, 680.

During assembly, the heat absorption portions 42 of the first heat pipes 40 are fixed in the grooves 124 of the base 122 by solder. The heat absorption portion 52 of the second heat pipe 50 is fixed in the slot 142 of the substrate 10. The first, second, third and fourth fin units 62, 64, 66, 68 are arranged on the substrate 10 in series, with one of the lateral walls 682 of the fourth fin unit 68 positioned on the step 142 of the supporting bar 14, whereby the fin assembly 60 is supported by the supporting bar 14. The heat dissipation portions 44 of the first heat pipes 40 are received in the first holes 63 of the second, third and fourth fin units 64, 66, 68, and attached to the first main body 620 of the first fin unit 62. One of the heat dissipation portions 54 of the second heat pipe 50 is received in the holes 602 of the fourth and third fin units 68, 66 and corresponding second holes 641 of the second fin unit 64 in series and is attached to the first main body 620 of the first fin unit 62. Another heat dissipation portion 54 of the second heat pipe 50 passes through the receiving space 690 and is received in other corresponding second holes 641 of the second fin unit 64 in series and is attached to the first main body 620 of the first fin unit 62.

The fan 20 is fixed in the holder 32 by the fasteners 34. Specifically, each fastener 34 is received in each hole 3223 of each first ear 3222 and each positioning hole 24 of the fan 20. The frame 22 is sandwiched between the abutting portion 344 and the sandwiched portion 342 of the fastener 34. The first ear 3222 is sandwiched between the sandwiched portion 342 and the head portion 340 of the fastener 34. The frame 22 of the fan 20 is segregated from the first ears 3222 of the holder 32 by the sandwiched portions 342 of the fasteners 34. Since the first connecting portion 341 is slightly shorter than the thickness of the first ear 3222, and the second connecting portion 343 is slightly shorter than the depth of the positioning hole 24 of the fan 20, the fastener 34 undergoes elastic distortion and generates a force to fittingly engage the first ears 3222 of the holder 32 with the fan 20. The second ears 3226 of the holder 32 are spaced from the fan 20. The fan 20 with the holder 32 is received in the receiving space 390, with the first fixing tabs 3224 fixed to a bottom surface of the main body 12 of the substrate 10 by fasteners (not shown), and the second fixing tabs 3228 fixed to a bottom surface of the main body 680 of the fourth fin unit 68 by fasteners.

In use, cooling air generated by the fan 20 flows not only through the channels of the fin assembly 60, but also through the holes 61 of the fin assembly 60. Since the fan 20 and the holder 32 are elastically segregated by the sandwiched portions 342 of the fasteners 34, and the fan 20 is spaced from the second ears 3226, the vibration of the fan 20 is not directly transmitted to the fin assembly 60 via the holder 32. Thus, vibration of the fin assembly 60 from the fan 20 is lessened, and undesirable noise generated thereby eliminated.

It is believed that the present disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure. 

1. A heat dissipation device comprising: a substrate; a fin assembly comprising a first fin unit located on the substrate and a second fin unit located on the first fin unit, the second fin unit comprising a plurality of parallel fins with a plurality of channels defined between the fins, a receiving space being defined in the fin assembly; and a fan fixed on the substrate by a securing device, the fan comprising a frame with positioning holes defined in the frame, and the securing device comprising a holder and a plurality of fasteners, the fasteners extending through the positioning holes of the frame to secure the fan to the holder and segregating the fan and the holder, the fan with the securing device being received in the receiving space of the fin assembly.
 2. The heat dissipation device as claimed in claim 1, wherein each of the fasteners comprises a head portion, a first connecting portion, a sandwiched portion, a second connecting portion, an abutting portion, and an inserting portion in series, the sandwiched portion segregating the fan and the holder.
 3. The heat dissipation device as claimed in claim 2, wherein the abutting portion is tapered to facilitate insertion of each fastener into a corresponding one of the positioning holes of the fan.
 4. The heat dissipation device as claimed in claim 2, wherein the frame of the fan is sandwiched between the abutting portion and the sandwiched portion, and the holder is sandwiched between the head portion and the sandwiched portion, whereby the fan is fixed on the holder by the fasteners.
 5. The heat dissipation device as claimed in claim 4, wherein the holder comprises a top plate and two lateral plates extending from the top plate, a plurality of first ears extending from the lateral plates through which the fasteners pass, the first ears being sandwiched between the head portion and the sandwiched portion.
 6. The heat dissipation device as claimed in claim 5, wherein the fasteners are elastic and the first connecting portions thereof are shorter than a thickness of the first ears of the holder, the second connecting portions thereof are shorter than a depth of the positioning holes of the fan.
 7. The heat dissipation device as claimed in claim 5, wherein the holder further comprises at least one first fixing tab extending from one of the first ears and fixed to the substrate.
 8. The heat dissipation device as claimed in claim 5, wherein the holder further comprises a plurality of second ears extending from the two lateral plates and spaced from the fan, and a plurality of second fixing tabs extending from the second ears fixed to the fin assembly.
 9. The heat dissipation device as claimed in claim 1, wherein the substrate comprises a main body and a supporting bar extending from the main body, a slot being defined between the main body and the supporting bar, the main body defining a plurality of grooves therein.
 10. The heat dissipation device as claimed in claim 9, further comprising a plurality of first heat pipes and a second heat pipe connecting the substrate and the fin assembly, wherein each of the first and second heat pipes comprises a heat absorption portion and two heat dissipation portions extending from the heat absorption portion, the heat absorption portions of the first heat pipes being received in the grooves of the main body of the substrate, the heat absorption portion of the second heat pipe being received in the slot of the substrate.
 11. The heat dissipation device as claimed in claim 10, wherein the fins of the second fin unit each comprise a main body and two flanges extending therefrom, the first fin unit comprises a main body and two lateral walls extending therefrom, and one of the lateral walls is located on a step formed on a top of the supporting bar of the substrate.
 12. The heat dissipation device as claimed in claim 11, wherein the main bodies of the first and second fin units each define a plurality of first holes through which the heat dissipation portions of the first heat pipes extend, a second hole through which one heat dissipation portion of the second heat pipe extends, and a receiving hole, the receiving holes cooperatively forming the receiving space receiving the fan therein, and another heat dissipation portion of the second heat pipe passing through the receiving space and attached to the main bodies of the first and second fin units.
 13. The heat dissipation device as claimed in claim 12, wherein the fin assembly further comprises a third fin unit located on the second fin unit, the third fin unit comprising a plurality of fins and defining a plurality of holes through which the heat dissipation portions of the first and second heat pipes extend.
 14. The heat dissipation device as claimed in claim 13, wherein the fin assembly further comprises a fourth fin unit covering the third fin unit, the first, second, third and fourth fin units defining a plurality of openings therein through which cooling air generated by the fan flows.
 15. A heat dissipation device comprising: a substrate comprising a main body and a supporting bar extending upwardly therefrom; a fin assembly located on the substrate and comprising a plurality of parallel fins, each comprising a main body and two flanges extending downwardly therefrom; a fan comprising a frame with positioning holes defined in the frame; and a securing device fixing the fan to the main body of the substrate, the securing device comprising a holder fixed to the main body and a plurality of elastic fasteners, the fasteners securing the fan onto the holder, each comprising a sandwiched portion sandwiched between the fan and the holder to segregate the fan from the holder.
 16. The heat dissipation device as claimed in claim 15, wherein each of the fasteners comprises a head portion, a first connecting portion, the sandwiched portion, a second connecting portion and an inserting portion in series.
 17. The heat dissipation device as claimed in claim 16, wherein the holder comprises a plurality of first ears and a plurality of first fixing tabs extending therefrom, the first ears being inserted by the first connecting portions of the fasteners and sandwiched between the head portions and the sandwiched portions, and the first fixing tabs being fixed to the main body of the substrate.
 18. The heat dissipation device as claimed in claim 17, wherein the holder further comprises a plurality of second ears and a plurality of second fixing tabs extending therefrom, the second ears being spaced from the fan, and the second fixing tabs being fixed to the fin assembly.
 19. The heat dissipation device as claimed in claim 15, wherein the supporting bar defines a step at a top thereof, receiving one flange of the fin assembly thereon.
 20. The heat dissipation device as claimed in claim 15, wherein the fin assembly defines a receiving space receiving the fan and the securing device therein. 